Vacuum clothes dryer



April 24, 1962 c. w. LAMBERT VACUUM CLOTHES DRYER 2 Sheets-Sheet 1 Filed Dec. 7, 1959 INVENTOR.

April 1962 c. w. LAMBERT 3,030,712

VACUUM CLOTHES DRYER Filed Dec. 7, 1 959 2 h ts-Sh 2 ah? T. 70% 71 I 67 I 66 lOl IN V EN TOR.

United States Patent 3,030,712 VACUUM CLOTHES DRYER Chandley William Lambert, 6325 Mackenzie Road, North Olmsted, Ohio Filed Dec. 7, 1959, Ser. No. 857,828 4 Claims. (Cl. 34-92) The invention relates to a method of drying clothes in a partial vacuum at reduced pressure and medium temperature.

Many conventional clothes dryers roast the fabric at high temperature for a long time and beat the brittle fibers into lint in a rapidly rotating drum.

Since water evaporates at a much lower temperature when the pressure is reduced, a vacuum dryer operates at a medium temperature, less lint is formed and the fabric lasts much longer.

One form of the vacuum clothes dryer is shown in the accompanying drawing.

FIG. 1 is a longitudinal cross section through the stationary vacuum drum and interior rotatable basket. Also shown are the vacuum pump, the rotative and heating systems and controls for them.

FIG. 2 is a transverse cross section showing the method of framing and some details of attached parts.

FIG. 3 shows the operation of the basket cover.

FIG. 4 shows a method of operating the electrical control switch.

PEG. 5 shows a conventional form of electric motor brake but since this is old in the art it is not specifically claimed except as a part of a complete new machine.

In FIG. 1, 1 is the cylindrical part of the vacuum drum which has curved round ends 18 and 19. End 18 is removable. 2 is the cylindrical perforated part of the rotatable clothes basket, which is secured to circular end plates 73 and 74. Shaft 4 rotates in pressure bearing 5 in drum end 19 and in bearing 6 which is secured to frame 3. On the left end of basket 2 is a bearing 7 which is secured to and turns with basket end plate 74. Short non-rotatable shaft 11 is secured to the inner side of end plate 18 of the vacuum drum. Splined hub 72 is secured to basket end plate 73 and fits on to splined end 71 of shaft 4.

At 2A is indicated a small portion of perforated basket 2.

To shaft 4 is secured a large pulley 12 which is belt connected to small pulley 13 on shaft 14 to which gear 15 is also secured. Worm gear 16 on the shaft of motor 17 meshes with gear 15. Coil 64 cooperates with brake wheel 65 as specified later in conneciton with FIG. 5.

Air, vapor and water are taken from the drum at 21, FIG. 1, by pump 22 and discharged at 23. Pump 22 is coupled at 24 to motor 25. The pressure within the drum is indicated by vacuum gauge 112.

Air is taken in at 26 and passes through air heater 27 and is released by reducing valve 32 to warm air pipe 33 and enters the drum interior through flat porous conductor 34.

Handle 35 is secured to rod 36 to which links 41 and 46 are pivoted. The links are pivotally secured to lever arms 42 and 47 which are secured to shafts 43 and 51 respectively.

Cam 44 on shaft 43 can depress pin 45 and release a free flow of air through reducing valve 32, relieving the partial vacuum in the drum so that door 81 can be raised.

Collar 37 is secured to rod 36 and compression spring 38 acts to return rod 36 to the raised position where shown.

Cam 52 on shaft 51 can raise small jack shaft 39, compressing spring 53. To shaft 39 are secured a short wing 54 and a longer double wing 55 which operate 3,030,712 Patented Apr. 24, 1962 switch handle 56 of toggle switch 57 as explained in connection with FIG. 4.

The switch 57 may be operated by turning handle 61 which is connected by small gears 49-48 to shaft 39.

Within drum 1 are baflie plates 84 and which enclose the lower part of basket ends 74-73. Brackets secured to baflie plate 84 support screen 82 which extends across the entire end of the drum. A closed clean out hole on the side of the drum is indicated at 83. The principle function of screen 82 is to prevent any objectionable substance from entering suction line 21.

To the exterior of basket 2 are secured soft flexible slings 86-87 which lightly contact the smooth sides of bafiie plates 84-85.

The curved basket cover 75 slides in parallel guides 76-77 as related with FIG. 3.

To the side of pulley wheel 12 is secured a projecting lug 63 whose purpose is to turn 0 switch 57 in a predetermined relation to basket rotation so that the basket stops with cover 75 spotted directly below drum door 81, as explained in connection with FIG. 4.

At 28 is a heating unit secured to the bottom of the drum. At 28A is indicated an insulated electrical resistance heating cable in radiant heater 28. The heat radiates through the drum Wall. Heating units 27-28 are controlled by thermostatic switches 31-29 respectively.

In FIG. 2 braced brackets, as 3A, support angle pieces, as 68, secured to the sides of drum 1. The drum door 81 is hinged at 88. Handle 89 operates a simple exterior spring door latch (not shown) which holds the door closed until the inside vacuum builds up.

Curved basket cover 75 slides in guides, as 77, and an outward projection 90 comes to position 90A when the cover is open. At position 90A, projection 90 may contact fixed lug 91 secured to the inner surface of drum 1, which is explained in connection with FIG. 3.

FIG. 3 shows a portion of basket cover 75 to which are secured pairs of guides 94-95-96. Between these guides are fiat slidable bars 92-93 to which are secured cross pieces 97-98 and downwardly projecting pins 102-103 respectively. The outer ends of bars 92-93 are turned up at 90 and 110 forming short projections.

Cover 75 is slid-able in parallel guides 77-76. Coiled tension springs 99-100 are secured to cross bars 97-98 and tend to pull bars 92-93 toward each other. When the cover 75 is opened by pushing on handle 10 or 40, pins 102 and 103 slide along the outer edges of guides 104 and 105 and are held against these guides by the increasing tension on springs 99-100 as bars 92-93 separate.

As soon as pins 102 and 103 reach the parallel parts of guides 104 and 105, the bars 92 and 93 are extended so that projections 90 and are rotatively in line with fixed lugs 91 and 111 as mentioned in connection with FIG. 2.

When the cover 75 is closed or retracted by hand, the pins 102 and 103 enter the grooves between guides 104-106 and between guides 105-107 respectively.

If the basket 2 is started rotating with cover 75 open, the lugs 91-111 hold the cover still while the basket rotates beneath it. When the cover is nearly closed, the projections 90 and 110 lose contact with lugs 91 and 111 and the springs 99-100 complete the closing.

To the paired guides 94-95-96 is secured a cover plate which holds the bars 93-92 between the guides. This plate is rounded over and down, as at 101, to enclose the moving parts and springs.

In FIG. 4, wings 54 and 55 are secured to shaft 39. In normal running position with switch handle 56 to the right in on position where shown, lug 63 secured to 3 pulley 12 passes above short wing 54 as indicated in FIG. 1.

When stop button 35 is pushed down, manually or otherwise, cam 52, FIG. 1, raises shaft 39 and when lug 63 contacts Wing 54, wing 55 snaps switch handle 56 to the left to the o position 56A, cutting oil? the electric current. Motor 17 is stopped immediately by the motor brake of FIG. 5.

In FIG. is shown coil 64, shown secured to motor frame 17 of FIG. 1. Brake drum or pulley 65 is secured onto the motor shaft and is contacted, FIG. 5, by brake shoe 66 secured to arm 67 which is pivoted at 69 and held down by brake spring 70 which is adjustable by screw 78 for braking contact pressure. Armature 79 and projection 80 are secured to collar 2109 which is pivoted at 108. Projection 80 contacts, arm 67.

When the switch 57 is closed by turning handle 61, FIG. 1, the motor 17 and coil 64 are energized, pulling magnetic armature 79 to the right and raising arm 67. This releases brake shoe 66 from brake drum 65 and motor 17 starts. When the current is cut off, as related in connection with FIG. 4, spring 70 puts the brake on and the motor shaft stops revolving immediately and basket cover 75 is spotted under drum door 81.

The reducing valve controls the flow of heated air into the interior of the drum. As is normal in reducing valves, it is responsive to changes of pressure on the secondary or low pressure side of the valve. When the pressure is reduced, by the continuously operating suction pump, below that limit for which the valve is set, the valve opens and allows a flow of warm air into the drum. When the pressure Within the drum rises to the upper setting of the valve, the valve closes.

Since the suction pump is in continuous operation, the low pressure limit is again soon reached and the operation of the reducing valve is repeated. The removal of moist air is continuous. The inflow of warm air is intermittent.

This type of basket stopping and cover spotting device is superior in operation in that the momentum of the rapidly rotating motor rotor is smoothly and rapidly decelerated without mechanical shock or jar.

In operation, the continuously running vacuum pump rapidly reduces the air pressure inside of the stationary drum. As soon as the lowering pressure reaches the low setting of the reducing valve, the valve opens and allows a flow of warm air into the drum. The pressure within the drum quickly rises to the high setting of the reducing valve and the valve closes.

Since the vacuum pump and motor are in continuous operation during the entire drying operation, the pressure within the drum rises and lowers between relatively narrow limits in intermittently recurring breathing cycles.

By the continuous addition'of heat to the drum interior, by the introduction of warm air and by the external drum heater 28, the tendency of the clothes within the drum to cool to the point of no evaporation is overcome and evaporation is continuous.

The vapor laden air is rapidly pumped out and replaced by less humid warm air from the air heater by the periodic opening of the reducing valve.

The thermostatic controls 29 and 31 prevent overheating and fiber roasting.

When stop button 35 is depressed, air is let into the vacuum drum. Obviously drum door 81 cannot be opened until the vacuum inside the drum is brought up to atmospheric pressure.

If the machine is started without closing the basket cover, no damage results since the basket cover is auto matically closed when rotation starts. H

When the warm wet clothes are put into the dryer, every fiber is soft and pliable. As soon as the partial vacuum is established, the fibers expand and are dried h in that condition. The result is a softness and fiufliness not otherwise possible.

If it is desired to have a timing mechanism by which the dryer is shut down at the end of a certain length of time, this is easily accomplished by having the timer depress rod 36 at the end of the drying cycle.

What is claimed is:

1. A vacuum type dryer comprising a stationary pressure tight drum secured within a frame; a rotatable basket within said drum; said basket secured to a shaft rotatable in a pressure tight bearing in said drum and having a pulley secured to said shaft exterior to said drum; a lug secured to said pulley rotatably disposed to operate a switch controlling a motor connected to said pulley; an air heater connected to said drum through a reducing valve controlling the flow of heated air into said drum; a vacuum pump connected to said drum; an air screen within said drum; and a slidable basket cover rotatively alignable with a pressure tight cover of said drum.

2. The combination of a vacuum drum; a rotatable basket within said drum; said basket secured to a shaft which extends through a pressure tight bearing in said drum; a pulley on said shaft exterior of said drum; a lug on said pulley rotatively positioned to operate a control switch; a 'motor and a motor brake connected to said switch; said motor mechanically connected to rotate said pulley and said shaft; an air heater connected through a reducing valve to the interior of said drum; and a pump connected to said drum reducing the pressure within said drum by evacuating moisture laden air from said drum.

' 3. A vacuum clothes dryer comprising, a rotatable perforated basket secured to a shaft within a vacuum drum; a motor driven pulley secured to said shaft exterior to said drum; said shaft extending through a pressure tight bearing in said drum; a lug on said pulley rotatively operable to a switch controlling said motor and a brake on said motor; means for controlling the operation of said switch by said lug; a slidable cover on said basket closable by stationary lugs within said drum and positionally alignable with a. door of said drum when stopped by the action of said motor brake; an air heater connected to said drum through a reducing valve controlling the flow of heated air into the interior of said drum; a suction pump connected to said drurn continuously drawing humid air from the interior of said drum and maintaining a partial vacuum within said drum during the drying cycle of operation of said dryer; and means for allowing a free flow of into said drum at the endof said drying cycle.

4. A vacuum type clothw dryer comprising, a. basket rotatable in a drum by a shaft having an external motor driven pulley on which a lug is secured cooperrable to a switch controlling said motor and a motor brake for positionally stopping the rotation of said basket; on said basket a cover slidable in parallel guides and having tnansverse bars with pins contacting shaped guides; and lugs on said bars contactable to stationary lugs within said drum to close said cover; and a reducing valve controlling the fiow of heated air entering said drum from which drum humid air is taken through a filter screen by a continuously operating suction pump.

References Cited in the file of this patent UNITED STATES PATENTS 1,800,228 Pierce Apr. 14, 1931 2,555,821 Smith June 5, 1951 2,574,298 Smith Nov. 6, 1951 2,681,512 Armstrong June 22, 1954 2,748,496 Hellyer June 5, 1956 2,904,895 I Bochan Sept. 22. 1959 

